Record Warmth Outpaced Record Cold

 

D.C.'s Museum of Natural History

The Nation’s Capital has seen a similar trend in many urban areas for more record warmth than record cold.  While only six of the last 10 February’s have been warmer than average, three of those six were among D.C.’s 10 warmest February’s on record.  February 2017 and February 2018 finished as D.C.’s warmest and third warmest, respectively (dating back to 1871).

The Nation’s Capital averaged one February day with highs in the 70s and nearly three days of at least 60° since 1993.  It had only one record low February temperature in the last 50 years.  Prior to D.C.’s record low of 5° on February 20, 2015, Washingtonians hadn’t experienced record cold in February since 1970.  Meanwhile, dozens of record highs have been set in the Nation’s Capital during the month of February. 

Washington, D.C. had a total of 85 record high temperatures for the entire year over the 20 year-period through 2018.  That’s compared to only five record low temperatures.  Over the same time period, the Nation’s Capital had 184 record high-low temperatures.  That means the coolest temperature of the day was significantly warmer than the average low temperature.  At the same time, D.C. had only 20 record low-high temperatures (daily high temperatures that were much cooler than average).

As suburban sprawl has continued, these warmer temperatures have extended further and further beyond downtown areas.  Dulles Airport in Sterling, Virginia, for example, had 188 record high temperatures during the last 20 years, compared to 50 record low temperatures.  Dulles also had 310 record high-low temperatures compared to 144 record low-high temperatures. 

These national temperature trends coincide with an increased amount of urbanization and development, as well as an increase in greenhouse gas emissions.  Locally, the much higher frequency of record heat compared to record cold can also be attributed to population density, which is much greater in the DC Metro Area today compared to the 1980s and 1990s.

NOAA’s Climate Prediction Center expects February 2022 to be a warmer than average month with near average precipitation.  That’s noteworthy since NOAA updated its weather averages last spring to reflect the 30-year period from 1991-2020 that replaced the previous data set from 1981-2010.  Average temperatures rose in the Nation’s Capital during the entire year during the decade of the 2010s that NOAA used to calculate the new temperature averages (the 2010s replaced the 1980s in the new data set).  That means warmer than average temperatures are now warmer than they were compared to the new daily and monthly temperature averages.